1. Field of the Invention
This invention relates generally to networks that require Quality-of-Service (QoS) parameters for data traffic streams, such as streaming audio and/or video (audio-video or “AV”), and more particularly to a system and method for configuring QoS in a network segment that has an intermediate device located between the source device and sink device.
2. Description of the Related Art
Quality-of-Service (QoS) in the field of packet-switched networks refers to a broad collection of networking capabilities and techniques to assure that a packet succeeds in passing between two points in the network. QoS elements of network performance typically include bandwidth (throughput), latency (delay), and error rate. The goal of QoS is to improve the user experience of a network's ability to deliver predictable results for sensitive applications. Certain types of network traffic, such as streaming AV, may require QoS to guarantee throughput. These types of traffic require a certain level of bandwidth to function—any more than required is unused, and any less will render the service non-functioning.
QoS is becoming increasingly important in local area networks (LANs) used in the home. These LANs may use a wide variety of existing cabling or non-engineered placement of wireless access points with technologies that have varying underlying bandwidth. Home networking equipment is typically installed by users with no knowledge of networking management and no desire to actively manage their networks. Furthermore, applications in the home tend to be AV-intensive with different bandwidth characteristics. Home LANs typically include wired LANs, like 10/100baseT Ethernet, and wireless local area networks (WLANs), such as those based on the well-known IEEE 802.11 or Wi-Fi standards. Other types of WLANs include ultrawideband (UWB) networks that have a fairly short range but very high throughput. Another type of LAN, one that does not use wireless transmission, is a powerline communications (PLC) network that uses the existing electrical wiring in a home or single building, such as a PLC network based on the HomePlug™ standard.
The setup or configuration of QoS in home network devices, such as consumer electronic (CE) devices like stereo receivers, digital video recorders (DVRs), digital TVs and AV servers, is important for AV applications. In a home network AV application the source device for the AV traffic stream is the media server, such as a personal computer (PC) or DVR, and the sink device is the media renderer, such as a digital TV. To set up QoS for a given AV application requires cooperation between QoS signaling and underlying L2 (Layer 2 in the Internet protocol (IP) stack) network QoS setup. The signaling informs the underlying L2 of the QoS parameters for the AV application. A difficulty arises in QoS setup if the home network has multiple network segments with the media server on one segment and the media renderer on another segment. A segment refers to a section of a network that shares a common physical medium. The boundaries of a network segment are established by devices or nodes, such as routers, bridges and hubs, that are capable of regulating the flow of traffic into and out of the segment. QoS setup in a network with multiple segments requires that the intermediate device or node between the segments know the QoS parameters for the AV application so that it can configure QoS in its network segment.
Currently there are no simple methods for QoS setup of a network segment in a network having multiple segments connected by an intermediate device. In an approach proposed by the Universal-Plug-and-Play (UPnP™) forum, a QoS manager (QM) needs to signal each network device along the path of the AV traffic stream. This requires the QM to discover the path of the AV traffic stream and then send QoS parameters to each of the devices along the path. However, this method is considered relatively complex. In another proposed approach, QoS signaling occurs only to the two end devices, i.e., the source and sink, and the intermediate device is required to measure the AV data to determine the QoS parameters. However, in this method, the accuracy and speed of the measurement may make the QoS setup in the segment unreliable.
What is needed is a system and method for simple and reliable QoS configuration of a network segment in a network having multiple segments connected by an intermediate device where there is only QoS signaling to the two end devices.